I have long been a fan of LEGO. Some of my earliest memories are playing with these plastic building blocks and making up the craziest looking constructions (that were often incomprehensible except to myself). Growing up, I wasn't even really aware that LEGO sets came with instructions. Nor was I aware of the existence of expert or technical sets (such as the Technic line of LEGO) until my senior year in college where we used a large collection of loose pieces in a mechatronics class to build self driving vehicles. After that, I was hooked, but I didn't really know what to do with them or how to build anything with intention. Over the years, I collected a few sets and built them (most recently a remote control excavator), but it wasn't until I read The Unofficial LEGO Technic Builder's Guide by Pawel "Sariel" Kmiec that I actually felt that I was learning how to really build and started to truly understand the mechanics behind it all.

This book is the ultimate reference guide / helper when working with LEGO Technic pieces. Kmiec discusses the different types of LEGO Technic pieces from beams to gears to bushings to pins organized neatly into different related sections. For example, Chapter 5 Gears and Power Transmission Basics provides not just an inventory of the gears available but also a discussion on backlash (the amount of play between gears that have been mated), efficiency, rotational direction, and more. Another example is shown on the left where Kmiec describes the different pins that are commonly available and their differences.

One of my favorite chapters was Chapter 7 Levers and Linkages where I not only learned how to best use LEGO pieces for transforming one motion into another, but also found that I was learning mechanics (and in a few cases relearning forgotten information). Seeing concepts like mechanical advantage not just discussed or demonstrated on paper but being able to build a tangible example helps cement the concept and its usage into the mind. If only I had read this book and played around with these LEGO pieces back in high school!

There were a ton of sections that I read with great interest as I had never even considered the issues or problems with building with LEGO (and, by extension, real life). One example that stands out in my mind is the discussion on the need for different turning radii of inner and outer turning wheels as well as how Ackermann steering geometry works and how to construct linkages to prevent tire slippage.

I was thinking about including the table of contents here as a way to show how complete this book is, but once I took another look at it, it seemed to be way to long. The book really does cover all the basics and then builds on those for more complex concepts including eleven different transmissions ranging from a 2-speed synchronized transmission to a 5-speed linear transmission to a continuously variable transmission (using rubber bands in lieu of hydraulics), a variety of different suspensions, pneumatic engines, and more. You can check out the table of contents and view several pages with Amazon's Look Inside Feature.

This book is highly recommended for anyone who is interested in mechanics or just likes playing with LEGO.